Optical lenses have become ubiquitous over the past several decades and are now used in a wide range of applications in a variety of fields, including consumer products (e.g. cameras, camcorders, cellular telephones, telescopes, etc), civilian and military surveillance, optical microsurgery, and endoscopic visualization. A conventional optical lens is typically made of transparent material and has a concave or convex shape that is tailored to suit a specific application. Particularly, a conventional lens is designed with a “focal length” that is generally determined by the curvature of the lens. “Focal length” is the distance over which initially colineated rays of light passing through a lens are brought to a focus (i.e. converged).
Shortcomings of conventional optical lenses include that the focal length of such a lens is fixed after fabrication. Focusing on objects that are positioned at varying distances from the lens therefore requires physical movement of the lens toward and away from the objects. Furthermore, the field-of-view of the lens is limited and is coupled to the focal length. That is, it is difficult to simultaneously obtain a long working distance and a wide field-of-view. Still further, a single lens component can only focus on a single viewing field at a certain distance from the lens at a given time. As a result, the lens cannot be used to acquire three-dimensional imaging with depth perception in real-time.
Looking to the natural world, one can find examples of optical lenses that overcome some of the limitations discussed above incorporated into the physiology of various animals. For example, predatory mammalian animals typically have a pair of forward-looking camera eyes, each having a single lens with an adaptively adjustable focal length for obtaining a clear image of objects at various distances. Numerous ocular nerves in the eyes of such animals provide relatively high definition images. However, due to their position and orientation, mammalian camera eyes cannot provide a wide field-of-view.
In contrast to the camera eyes of mammals, flying insects have compound eyes that are composed of hundreds, and in some cases thousands or millions, of small eyes (ommatidia) that are arranged on a generally spherical underlying structure. In these species, each small eye (ommatidium) has a fixed focal length and is responsible for providing a view of a certain field ahead of it. A single nerve corresponds to each ommatidium and delivers one pixel to the vision process center in the brain of the insect where a complete, unified image is created. Compared to a camera eye, the compound eye usually has poor resolution, which is generally attributable to the poor image processing capability of an insect's small brain. However, because of the spherical configuration of the compound eye and the resulting orientations of the numerous ommatidia distributed thereon, the eye provides a much wider field-of-view compared to a camera eye.
The need exists for an optical lens system that overcomes the disadvantages of the prior art and would be suitable for a variety of commercial and non-commercial applications. Specifically, it would be advantageous to provide an optical lens system that features a wide field of view, variably adjustable focal length, high definition images, and is relatively small in size and inexpensive to produce.